Ozzy Osbourne has joined together with Slipknot's Corey Taylor to combine their respective festivals into one huge weekend metal event this fall. Black Sabbath will headline the Saturday bill, while Slipknot headlines on Sunday.

Called Ozzfest Meets Knotfest, the festival will be held Sept. 24 and 25 at the San Manuel Amphitheater and festival grounds in San Bernardino, Calif. Tickets go on sale May 20. Sharon Osbourne, Ozzy's manager and recently estranged wife, made the announcement today at the Palladium in Hollywood. She brought Geezer Butler onstage, as well.

Ozzfest Meets Knotfest's Sept. 24 lineup also includes Megadeth, while Slayer and Anthrax will be part of the event's Sept. 25 slate. The main stage on both days will be paired with a second stage named in honor of the late Lemmy Kilmister.

Ozzfest began in 1996, and continued as an annual traveling U.S. festival through 2007. A single-night edition featuring Metallica was held in Dallas in 2008 before Ozzfest took a year off. The event then returned with a six-date tour in 2010, featuring a bill that included Osbourne, Motley Crue and others. After that, Ozzfest was held in 2013 and 2015 in Japan, first at Chiba and then in Tokyo. Black Sabbath, who are mounting a final tour with Osbourne through the fall, were originally scheduled to perform at the 2015 edition but they were replaced by Ozzy and Friends.

Knotfest, curated by Slipknot, was founded in 2012. The inaugural version was a two-night event, while the second was presented at Makuhari Messe in Tokyo – the same venue that played host to Ozzfest last year. The 2014-15 editions of Knotfest were also held in San Bernardino.

Knotfest had already announced Nov. 5 and 6 dates in Japan, with more than 20 bands playing over the course of the weekend. Slipknot are also touring with Marilyn Manson in support of their newest album, .5: The Gray Chapter, this summer.

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